Can You Take L-Theanine With Coffee? A Simpler Way With d9-Caffeine

Yes, you can take L-theanine with coffee, and plenty of people do. It is how many people first try the caffeine and L-theanine pairing. The catch is that coffee makes the pairing hard to dose consistently. Here is what the research actually used, where the coffee version falls short, and a simpler alternative built on d9-caffeine.

Why people pair L-theanine with coffee

Coffee contains caffeine but no L-theanine, an amino acid found naturally in tea. Adding L-theanine recreates the pairing tea drinkers get naturally, and it is one of the most studied combinations for focus. A 2014 meta-analysis found that caffeine with L-theanine improved attention-switching and alertness in the first two hours after taking it. Our post on why d9-caffeine and L-theanine are paired covers the research.

What the studies actually used

The doses in the best-known studies were modest: 50 mg of caffeine with 100 mg of L-theanine in a 2008 study of 27 adults, and 40 mg of caffeine with 97 mg of L-theanine in a 2010 study of 44 adults. That is about two parts L-theanine to one part caffeine, with far less caffeine than a typical coffee. An 8-ounce cup has about 95 mg, and coffee shop sizes often have much more.

Where the coffee version falls short

• The caffeine dose is a moving target. Bean, roast, brew method and cup size all change it, so your ratio changes from cup to cup.
• Coffee usually means more caffeine than the studies used. A large coffee can hold several times the caffeine in the studied pairings.
• Coffee fades on the regular caffeine timeline. With a half-life around five hours, the morning cup is fading by early afternoon, and the afternoon refill can reach into your night.
• It is two products to buy, measure and remember.

A simpler way with d9-caffeine

Caffeine 2.0 + L-Theanine puts both in one capsule: 22.5 mg of d9-caffeine and 50 mg of L-theanine. d9-caffeine is caffeine with nine hydrogen atoms replaced by deuterium, which slows how fast the liver breaks it down. In a 2022 double-blind study in 20 healthy adults, it was absorbed as quickly as regular caffeine and produced four to five times the total exposure over time. One morning capsule gives you a fixed ratio and a longer curve, with no refill math.

If you are keeping your coffee

• Coffee with L-theanine is a reasonable choice. Keep L-theanine within your product's label, and keep total caffeine within the FDA's reference point of 400 mg a day for healthy adults.
• Want the ritual without the caffeine math? Some people switch their morning cup to decaf and take a capsule alongside it.
• Do not stack full-strength coffee on top of Caffeine 2.0 + L-Theanine casually. Both are caffeine, and they add up.

Curious how tea compares? See matcha vs coffee vs d9-caffeine.

Who should check with a physician first

Skip it, or talk to your physician first, if you are pregnant or breastfeeding, under 18, sensitive to caffeine, or have a heart condition, high blood pressure, an arrhythmia, an anxiety disorder or a sleep disorder. Check with your physician or pharmacist if you take prescription medication, including blood pressure medication or sedatives.

How Vita Bloom fits

Caffeine 2.0 + L-Theanine pairs 22.5 mg of patented Deura9® d9-caffeine with 50 mg of L-theanine in every capsule. Start with one capsule in the morning, take up to four a day, and never exceed 90 mg of d9-caffeine.

Frequently asked questions

How much L-theanine should I take with coffee?

The well-known studies used about two parts L-theanine to one part caffeine, and L-theanine's GRAS notice covers up to 250 mg per serving. Follow your product's label.

Should I take L-theanine before or with coffee?

Together is fine. L-theanine reaches peak blood levels in under an hour, on a similar timeline to caffeine.

Can I drink coffee with Caffeine 2.0 + L-Theanine?

Decaf is the easiest match. If you drink regular coffee, count its caffeine and keep the total modest.

Does L-theanine cancel out caffeine?

No. In a 2008 study, L-theanine did not reduce caffeine's effect on alertness, though it did blunt caffeine's rise in blood pressure.

Deura9® is a registered trademark of Lennham Pharmaceuticals, Inc. under exclusive license to d9 Designs Inc.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.